It is well known to provide an air bag assembly including an inflatable air bag cushion for protecting the occupant of a transportation vehicle. In an automotive vehicle such air bag assemblies are typically located within the hub of the steering wheel and in a recess in the vehicle instrument panel for protection of the vehicle occupants seated in an opposing relation to such assemblies. Additional air bag assemblies may be located within the seats and/or door panels for protection of the occupants during a side impact event. Air bag assemblies typically include an inflatable cushion and a gas emitting inflator mounted in fluid communication with the inflatable cushion. In a driver side air bag module the air bag cushion typically includes a mouth disposed in substantially surrounding relation to the inflator with a perimeter portion of the mouth being held at a fixed position relative to the inflator. In a passenger side assembly the inflator is typically held within a trough-like housing with the air bag cushion being held within the housing such that inflation gas passes from the inflator into the cushion upon activation of the inflator.
In the past, it has been advocated to adjust the inflated profile of air bag cushions by the use of tethering elements which are set to effective operative lengths so as to contour the profile of the air bag cushion at full expansion. The tethering elements may be of either a fixed length in operative relation to the air bag cushion or may be adjustable so as to accommodate persons of different sizes and/or collision events of different severity levels. By way of example only, representative systems for use in effecting a controlled deployment depth of an air bag cushion by the selective adjustment of tethering elements are disclosed in U.S. Pat. No. 6,422,597 to Pinsenschaum et al. and United States Patent Application No. 2002/0036400 A1 in the name of Winters et al. which are both incorporated by reference as if fully set forth herein. While such systems are believed to be useful in providing air bag cushions with discrete contoured profiles, such systems provide for controlled cushion restriction substantially only upon full extension of the tethering elements. That is, the tethering elements are extended to their full operative length before exerting a substantial restraining influence on the air bag cushion.